This invention relates to a grenade-type projectile having a shaped charge liner and a fragment-forming, possibly pre-fragmented projectile housing. The projectile is designed for being fired, for example, from a 40-mm grenade pistol for use against armored targets and has a simultaneous side-spray effect. The grenade-type projectile has a range of about 300 to 400 m.
Grenade-type projectiles of the above-outlined type are fired from cartridge casings which are provided with a free space below the projectile bottom to serve as the gas pressure chamber. The propelling charge powder proper is disposed in a central propellant unit at the bottom of the cartridge casing.
Projectile and cartridge casing are conventionally connected with one another by a detent or snap-in connection; they may additionally be bonded together by an adhesive. To protect the projectile against environmental influences (moisture), the region of the connection is often also coated by a layer of protective lacquer. These measures, however, result in irregular forces that separate the projectile from the cartridge casing when fired, leading to non-uniform initial starting velocities and poor accuracy.
German Offenlegungsschrift (non-examined published application) 3,507,643, to which correspond U.S. Pat. Nos. 4,762,068 and 4,815,387, solved the above problem for a 40-mm caliber smoke-screen cartridge including a tracer lining by providing a firm and form-locking screw connection between a structurally long propellant unit and a thick-walled, rearwardly screwed-in smoke-screen projectile base. Once a desired break location has ruptured in the propellant unit, the front portion of the thread of the propellant unit remains attached to the projectile base, and a telescoping sleeve system is intended to initially prevent the propelling charge gases from reaching the free space in the cartridge casing at the beginning of projectile acceleration. Only after the telescoping sleeves, of which the inner sleeve remains connected with the projectile body, have been pulled apart and lose their sealing contact, will the propelling charge gases reach the already greatly enlarged free space in the cartridge casing. This, however, results in a considerable loss in pressure or in pressure fluctuations and no uniform acceleration can be realized for the projectile.
Since smoke-screen projectiles need not have as high a hit accuracy as live ammunition, the above-outlined known tear-away connection is well suited for smoke-screen projectiles or similar projectiles which include a tracer and other payload, such as charges generating a flash, noise, color and/or smoke. The prior art arrangement, however, is not suitable for live ammunition having a thin-walled base and no tracer lining, in which only little room is available in the cartridge casing below the projectile base.